Atypical Morphological Patterns of Topical Steroid-Modified Dermatophytosis: A Cross-Sectional Study in South Asia

Background: Dermatophytosis remains one of the most common superficial fungal infections in South Asia. During the last decade, irrational use of over-the-counter topical corticosteroid combinations has altered the clinical morphology, severity, and chronicity of infection. This modified presentation, often termed steroid-modified dermatophytosis or tinea incognito, delays diagnosis and contributes to persistent transmission. Objective: To evaluate the atypical morphological patterns, demographic profile, risk factors, and clinic mycological characteristics of topical steroid-modified dermatophytosis in a South Asian population. Methods: A hospital-based cross-sectional study was conducted among 1,000 consecutive patients attending dermatology outpatient departments between January and December. Patients with clinically suspected dermatophytosis and documented prior use of topical corticosteroid-containing preparations were enrolled. Detailed history, examination, lesion morphology, site distribution, family history, duration, source of steroid recommendation, and prior treatments were recorded. Potassium hydroxide (KOH) microscopy and fungal culture were performed where feasible. Data were analyzed using descriptive and inferential statistics. Results: Mean age of participants was 29.8 ± 12.6 years, with male predominance (58.4%). Most patients belonged to the 21–40-year age group (52.7%). Common sites included groin (62.1%), trunk (54.8%), face (18.3%), and multiple body sites (47.6%). The most frequent atypical morphologies were ill-defined erythematous plaques (38.9%), extensive concentric lesions (24.7%), pseudo eczematous plaques (18.5%), pustular lesions (7.8%), and atrophic telangiectatic lesions (5.2%). Chronic disease (>6 months) was noted in 41.3%. Fixed-dose steroid-antifungal-antibacterial combinations were used by 64.9% of participants. KOH positivity was 71.6%, while culture positivity was 48.2%. Significant associations were found between prolonged steroid use and extensive disease, recurrence, and atypical morphology (p<0.05). Conclusion: Topical steroid misuse has significantly transformed the clinical appearance of dermatophytosis in South Asia. Atypical presentations are common and frequently extensive, chronic, and recurrent. Regulatory control of irrational topical steroid combinations, public education, and clinician awareness are urgently required to reduce the burden of steroid-modified fungal infection.